Primary pulmonary rhabdomyosarcoma in a child, with a review of literature

Primary Pulmonary Alveolar Rhabdomyosarcoma in a Pediatric Patient: A Case Report With Literature Review

Rhabdomyosarcoma (RMS) is a rare soft tissue tumor originating from skeletal muscle that is mostly reported in children. The most common sites of involvement are the head, neck, and extremities. The 2020 WHO classification divide RMS into four types: embryonal, alveolar, pleomorphic, and spindle cell/sclerosing. Reports of RMS with primary lung origin are rare. We present a case of RMS in a 16-month-old boy who presented with a lung mass and microscopic examination with fluorescence in situ hybridization confirmed the diagnosis of alveolar RMS. In conclusion, RMS should be considered in the differential diagnosis of any lung mass with small round blue cell morphology in the microscopic evaluation and should be distinguished from metastatic RMS of other sites, pleuropulmonary blastoma, lymphoma, neuroblastoma, primitive neuroectodermal tumor (PNET)/EWING, and malignant peripheral nerve sheet tumors (MPNST).

Association between Congenital Lung Malformations and Lung Tumors in Children and Adults: A Systematic Review

INTRODUCTION

The appropriate management of asymptomatic congenital pulmonary malformations (CPMs) remains controversial. Prophylactic surgery is recommended to avoid the risk for development of pulmonary infections and to prevent the highly debated development of malignancy. However, the true risk for development of malignancy remains unknown. A systematic review analyzed all cases in which lung tumors associated with CPMs in both the pediatric and adult populations were described.

METHODS

A comprehensive literature search was carried out; it included all the cases in which an association between CPMs and malignant pulmonary lesions was reported.

RESULTS

In all, 134 publications were eligible for inclusion. In 168 patients CPM was found associated with lung tumor. The diagnosis was made in 76 children at a mean age of 3.68 ± 3.4, whereas in the adult population (n = 92) it was made at a mean age of 44.62 ± 16.09. Cough was the most frequent presenting symptom both in children and in adults. Most of the patients underwent lobectomy. The tumor most often associated with CPM was pleuropulmonary bastoma in children (n = 31) and adenocarcinoma (n = 20) or bronchioloalveolar carcinoma (n = 20) in adults. The CPM most frequenty associated with tumors in children was congenital cystic adenomatoid malformation (n = 37), especially type 1 (n = 21), whereas in adults it was bronchogenic cyst (n = 25), followed by congenital cystic adenomatoid malformation (n = 21).

CONCLUSIONS

CPMs should be followed up and never underestimated because they may conceal a tumor. Apparently, there is no age limit for malignant progression of CPMs and no limit of the interval between first detection of the CPM and appearance of the associated tumor.

Risk-reduction surgery in pediatric surgical oncology: A perspective

OBJECTIVE

A small percentage of pediatric solid cancers arise as a result of clearly identified inherited predisposition syndromes and nongenetic lesions. Evidence supports preemptive surgery for children with genetic [multiple endocrine neoplasia type 2 (MEN2), familial adenomatous polyposis syndrome (FAP), hereditary nonpolyposis colorectal cancer (HNPCC), and hereditary diffuse gastric cancer (HDGC) and nongenetic [thyroglossal duct cysts (TGDC), congenital pulmonary airway malformations (CPAM), alimentary tract duplication cysts (ATDC), and congenital choledochal cysts (CCC)] developmental anomalies. Our aim was to explore the utility of risk reduction surgery to treat and prevent cancer in children.

METHODS

A systematic review of the available peer-reviewed literature on PubMed was performed using a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) search strategy, where possible. Search items included "risk reduction surgery", "hereditary cancer predisposition syndrome", "multiple endocrine neoplasia type 2", "familial adenomatous polyposis", "hereditary nonpolyposis colorectal cancer", "hereditary diffuse gastric cancer", "thyroglossal duct cysts", congenital pulmonary airway malformations", "alimentary tract duplication cysts", "malignant transformation", and "guidelines".

RESULTS

We identified 67 articles that met the inclusion criteria describing the indications for prophylactic surgery in surgical oncology. For the genetic predisposition syndromes, 7 studies were related to professional endorsed guidelines, 7 were related to surgery for MEN2, 11 were related to colectomy for FAP, 6 were related to colectomy for HNPCC, and 12 related to gastrectomy for HDGC. Articles for the nongenetic lesions included 5 for techniques related to TGDC resection, 9 for surgery for CPAMs, and 10 for resection of ATDCs. Guidelines and strategies varied significantly especially related to the extent and timing of surgical intervention; the exception was for the timing of thyroidectomy in children with MEN2.

CONCLUSION

Current evidence supporting prophylactic surgery in the management of pediatric cancer predisposition syndromes and nongenetic lesions is best delineated for thyroidectomy to prevent medullary thyroid cancer in children with MEN2 (Strength of Recommendation Grade B/C). Despite the lack of pediatric specific evidence-based recommendations regarding the appropriate extent and timing for risk-reduction surgery for FAP, HNPCC, HDGC and nongenetic anomalies, our review represents an opportunity towards understanding the postgenomic development of these lesions and provides current indications and techniques for preemptive cancer prevention surgery in children.

The argument for operative approach to asymptomatic lung lesions

Antenatal detection of congenital pulmonary airway malformations (CPAM) has improved immeasurably from its initial application in the 1980s and probably encompasses >80% of all such lesions. Accurate diagnosis still remains less reliable and definitive diagnosis requires detailed anatomical imaging (typically with CT scan) in the post-natal period. About 10% of all lesions will present with symptoms during the neonatal period and the choice of surgical intervention is then easy. For those that remain asymptomatic then there is still a degree of controversy about elective surgical resection. This article presents the case for elective surgery within the first year of life and aims to quantify the risks of non-intervention such as abscess, empyema, recurrent pneumonia, air-leak, and pneumothorax and various types of malignancy in such cases. The current surgical approach now includes both open muscle-sparing thoracotomy and thoracoscopic resection.

Antenatal and postnatal management of congenital cystic adenomatoid malformation

Congenital thoracic malformations (CTMs) are a heterogeneous group of rare disorders that may involve the airways or lung parenchyma. The authors have focused on the condition that causes the most controversy, namely, congenital cystic adenomatoid malformation (CCAM). The reported incidence is 3.5 and 0.94 per 10,000 live births for CTMs and CCAMs respectively. Ultrasound is the antenatal imaging modality of choice for screening for CCAMs whilst magnetic resonance imaging is complimentary for morphological and volumetric evaluation of the foetal lung. Most CCAMs are detected antenatally with only a small proportion presenting postnatally. Only a few CCAMs cause foetal problems, with foetal hydrops being the best predictor of death. Although many CCAMs regress during pregnancy, most remain detectable postnatally by CT scans. Surgical excision of symptomatic lesions is relatively straightforward, but management of asymptomatic lesions is controversial. Some surgeons adopt a "wait and see" approach operating only on those patients who develop symptoms, but others operate on asymptomatic patients usually within the first year of life. Due to the potential of malignant transformation, children should have long term follow up. There is an urgent need to delineate the natural history of antenatally detected CCAMs to guide future management.

Long term respiratory outcomes of congenital thoracic malformations

The advent of universal antenatal ultrasonography in many countries has revealed the full spectrum of congenital thoracic malformations (CTMs) and presented clinicians with a number of practical dilemmas to do with diagnosis and management. We present a review of the most common forms of CTMs, including congenital cystic adenomatoid malformation, bronchopulmonary sequestration, and lobar and segmental emphysema.

Familial case of prenatally diagnosed intralobar and extralobar sequestrations with cystadenomatoid change

Hybrid lesions are part of a spectrum of rare pulmonary diseases that are characterized as having elements of both congenital pulmonary airway malformation and bronchopulmonary sequestration. Fetal thoracic masses arise from alterations during lung development that are separated by timing of the inciting event and are often associated with an underlying degree of bronchial atresia. There are a handful of documented reports of sequestrations occurring in siblings, but no known reports of prenatally diagnosed lesions occurring in families. We present a case of 2 siblings diagnosed prenatally with fetal thoracic lesions who underwent postnatal resection revealing hybrid lesions on pathologic examination. Newer radiologic techniques have increased our ability to detect these masses prenatally, as well as follow them throughout pregnancy to determine their natural history. Ongoing laboratory investigation into the etiology of congenital lung lesions has brought forth more questions and suggested a familial component at a cellular level that has not yet been fully discovered. We reviewed the current literature of factors contributing to the development of congenital lung lesions and suggest that there is a familial link in certain patient populations where screening may be indicated.

Cytogenetic and p53 profiles in congenital cystic adenomatoid malformation: insights into its relationship with pleuropulmonary blastoma

Congenital cystic adenomatoid malformation (CCAM), a developmental anomaly of lung, shares many features with the pediatric tumor pleuropulmonary blastoma (PPB). Both may show benign epithelium-lined cysts and mesenchymal proliferation, often with skeletal muscle differentiation. Before its recognition as a distinct entity, PPB was described in several reports as "rhabdomyosarcoma arising in CCAM." Abnormal karyotypes in PPB often show excess material from chromosome 8. It has also been suggested that PPB may harbor p53 mutations. We examined the karyotype and searched for p53 mutations (via immunostaining and single-strand conformation polymorphism analysis) in 11 CCAM and in 2 PPB. Karyotypes were normal in all CCAM and showed clonal abnormalities in both PPB. There was marked and diffuse immunopositivity for nuclear p53 in the epithelial cells of CCAM and PPB. Strong staining was also observed in approximately 50% of the stromal cells in all PPB, but was seen in the stroma of only 2 of 10 CCAM, where it was faint and focal. TP53 mutations were not identified in CCAM or PPB. We conclude that CCAM does not contain the clonal chromosomal aberrations reported in PPB and shows less stromal p53 immunostaining than PPB. Since p53 mutations were not identified in either entity, the observed p53 immunoreactivity may be caused by another mechanism; its role in PPB and CCAM pathogenesis remains to be determined. Overall, these findings provide evidence that CCAM is nonneoplastic. Although some may view CCAM as a PPB precursor, it remains biologically distinct in terms of karyotype and p53 status.

Rhabdomyosarcoma arising within congenital cystic adenomatoid malformation

Rhabdomyosarcoma arising within a congenital cystic adenomatoid malformation (CCAM) is an unusual entity. The patient underwent a lobectomy of his right lower lobe of lung due to a CCAM at the age of two. One year later, he developed a solid embryonal rhabdomyosarcoma at the same location. He received 1-year period chemotherapy and when the tumor reduced to a resectable size, surgical excision was done. The tumor cells appeared more differentiated after chemotherapy. The patient remains disease free to date, 16 months after surgery.

Primary rhabdomyosarcoma of the lung arising over cystic pulmonary adenomatoid malformation

The authors report the case of a 2-year-old girl with pulmonary cystic adenomatoid malformation type II who presented with a mass on the lower lobe of the left lung. Resection and histological examination revealed pleomorphic rhabdomyosarcoma. Chemotherapy and radiotherapy followed the operation and the girl is alive and in perfect condition 10 years after the operation. The literature on primary rhabdomyosarcoma of the lung in children is reviewed.

Asymptomatic congenital lung malformations

Congenital lung malformations are often discovered incidentally on routine prenatal sonography or postnatal imaging. Lesions such as congenital cystic adenomatoid malformations (CCAM), sequestrations, bronchogenic cysts and congenital lobar emphysema may be asymptomatic at birth or at the time of discovery later in life. Some authors advocate simple observation because of the lack of data on the incidence of long-term complications. However, there are very few described cases where CCAM and intralobar sequestration have remained asymptomatic throughout life; complications eventually develop in virtually all patients. The most common complication is pneumonia, which may respond poorly to medical treatment. Other complications include the development of malignancies (carcinomas and pleuropulmonary blastomas), pneumothorax and hemoptysis or hemothorax. Since lung resection will be required sooner or later for CCAM, intralobar sequestration and intrapulmonary bronchogenic cysts it is best not to wait for complications to occur. For patients diagnosed prenatally, we recommend surgery at 3 to 6 months of life at the latest, so that compensatory lung growth can occur. At this age the postoperative course is usually smooth and long-term follow-up has shown normal respiratory function. Mediastinal bronchogenic cysts also tend to become symptomatic and elective resection is recommended. On the other hand, asymptomatic congenital lobar emphysema may regress spontaneously and observation is warranted. The management of small noncommunicating extralobar sequestrations is more controversial; it is known that these lesions can remain asymptomatic throughout life but complications may develop and they are sometimes difficult to differentiate from neuroblastoma.

Current outcome of antenally diagnosed cystic lung disease

BACKGROUND/PURPOSE

The natural history of parenchymal lung lesions such as congenital cystic adenomatoid malformation (CCAM) and pulmonary sequestration (PS) has been altered by the advent of antenatal ultrasonography. Initial reports were characterized by a high (about 30%) incidence of adverse features (eg, hydrops) and a poor outcome and did not accord with our recent experience. The authors have reviewed the outcome of fetuses that had been diagnosed in a large tertiary referral fetal medicine unit with the aim of delineating current experience. The term cystic lung disease was used throughout to avoid unjustifiable histologic precision.

METHODS

The scans of all fetuses that had been diagnosed with cystic lung disease between January 1995 and July 2001 were reviewed. The outcome of each pregnancy was established, and, where possible, all infants underwent appropriate investigations, including thoracic computed tomography (CT) scans.

RESULTS

Sixty-seven fetuses had a cystic lung abnormality diagnosed from January 1995 to July 2001. The median (range) age at diagnosis was 21 (19 to 28) weeks. The lesion was right sided in 29 (43%), left in 36 (54%), and bilateral in 2 (3%); it was characterized as dominantly macrocystic in 27 (40%), microcystic in 35 (52%), and mixed in 5 (8%). Mediastinal shift was present in 30 fetuses (45%). Severe signs of fetal distress (eg, hydrops) were present in 5 fetuses (7%). Antenatal intervention was performed in 4 fetuses (thoraco-amniotic shunts [n = 3] and percutaneous intrauterine laser therapy [n = 1]). Sixty-four (96%) of the fetuses were born alive. There was 1 termination of pregnancy and 2 intrauterine deaths (all severe microcystic lesions). Forty-two infants (63%) underwent thoracotomy and appropriate excisional surgery at a median of 7.5 months (range, 1 day to 34 months). Two infants (which included the fetus having intrauterine laser therapy) died early in the postnatal period. Both were large microcystic lesions and had antenatal features of severe fetal distress. Twelve infants were investigated in the postnatal period but did not undergo surgery. Ten infants were not appropriately investigated or were lost to follow-up. Histologic examination showed definitive diagnostic features of CCAM (n = 25) or PS (n = 6). Other lesions with hybrid features of both were also seen (n = 11). There was a degree of correlation between antenatal ultrasound features (size of cyst [P =.03], in-utero behavior [P =.06], mediastinal shift [P = 0.05]) and the need for surgery but not with the final histologic diagnosis. Surgical excision was required in 45% of lesions showing late-gestation "resolution."

CONCLUSIONS

Antenatally diagnosed "cystic lung disease" has an excellent prognosis in the absence of signs of severe fetal distress. The need for surgery should be based on appropriate postnatal investigations (eg, CT scans), rather than on antenatal behavior.

Thoracoscopic lobectomy for prenatally diagnosed lung lesions

PURPOSE

The aim of this report is to assess the technique and outcome of thoracoscopic lobectomy for asymptomatic prenatally diagnosed lung lesions.

METHODS

From June 1999 to March 2002, 14 consecutive asymptomatic patients with a prenatal diagnosis of congenital cystic adenomatoid malformation or pulmonary sequestration, ages 3 to 15 months, underwent postnatal thoracoscopic lobectomy. Single-lung ventilation and controlled pneumothorax with low pressure (4 torr) and low flow (1.0 L/min) were used in all. Follow-up ranged from 4 to 35 months.

RESULTS

All procedures were completed successfully using 3 ports. Rather than using stapling devices or clips, pulmonary vessels were sealed and the fissure completed (when necessary) with the Ligasure thermal energy device. Eleven lesions were on the left (10 lower lobe), and 3 were in the right lower lobe. The mean operating time was 110 minutes. The average hospital stay was 38 hours. There were no intraoperative or postoperative complications.

CONCLUSIONS

This is the first report of a completely thoracoscopic technique for pulmonary lobectomy in small children. Thoracoscopic lobectomy is a relatively quick and safe procedure, and the cosmetic result is excellent. Early resection obviates the risk of infection in these lesions.

Management of asymptomatic neonatal cystic adenomatoid malformations

BACKGROUND/PURPOSE

Although much is known about the prenatal course of cystic adenomatoid malformations (CCAM), the postnatal course of asymptomatic lesion is less well documented. The authors studied the pre- and postnatal course and treatment of asymptomatic CCAM.

METHODS

The authors reviewed the files of all patients referred to Necker-Enfants Malades hospital with an antenatal diagnosis of CCAM and asymptomatic at birth.

RESULTS

Files of 29 patients were studied. The first x-ray film was considered normal in 12 cases (41.3%). Computed tomography was normal in 4 cases and showed cystic lung malformations in the other patients. Postnatally, clinical manifestations occurred in 3 patients (10.3%). CCAM vanished in 6 cases. Surgical resection of CCAM was performed in 17 cases (58.6%). All the patients currently are asymptomatic.

CONCLUSIONS

CCAM can shrink or vanish during pregnancy and antenatal ultrasound findings are not predictive of the postnatal course. Thus, all infants with prenatal diagnosis of CCAM require postnatal evaluation. Normal radiographic findings at birth do not rule out CCAM persistence on CT. The treatment of asymptomatic CCAM is controversial. Surgery may be advocated because of the low morbidity and the prevention of late complications, above all, cancer. The surgical indications of small (<3 cm) and asymptomatic lesions should be discussed on a case-by-case basis with the parents.

Congenital cystic lung disease: diagnostic and therapeutic considerations

Congenital lung cysts such as congenital cystic adenomatoid malformation, pulmonary sequestration, congenital lobar emphysema, and bronchogenic cysts are rare but fascinating anomalies of lung development. While there are many similarities in terms of their presenting features, there are particular differences between the diagnostic groups that are important to highlight, especially in relationship to approaches to imaging and long-term outcome. A case of each entity is presented with an emphasis on the contemporary approach to diagnostic investigations and therapeutic options.

Epithelial and soft tissue tumors of the tracheobronchial tree

This article provides a broad overview of tumors that can involve the tracheobronchial tree. For the most part, the clinical, radiographic, and endoscopic presentation of these rare tumors does not differ significantly from the more common tumors of the lung. Appropriate classification of many tracheobronchial tumors ultimately requires complete sampling and a thorough microscopic evaluation. The introduction of ancillary diagnostic techniques such as immunohistochemistry and molecular analysis will continue to refine tumor classification.

Primary pulmonary rhabdomyosarcoma arising within cystic adenomatoid malformation: a case report and review of the literature

The current report describes a 13-month-old boy with primary pulmonary rhabdomyosarcoma (RMS) that originated within a congenital cystic adenomatoid malformation (CCAM). To the best of our knowledge, he is the youngest patient of all primary pulmonary RMS cases reported in the English-language literature. The tumor, localized in left upper lobe, was removed completely, and histologic examination showed embryonal subtype. Postoperative systemic chemotherapy was carried out. Recent evaluation 15 months after resection has not identified any residual or recurrent disease. Primary pulmonary RMS, although very rare in the pediatric age group, should be considered in young patients with solitary pulmonary masses and associated cystic lesions.

Bronchioloalveolar carcinoma arising in congenital cystic adenomatoid malformation in a child: a case report and review on malignancies originating in congenital cystic adenomatoid malformation

A type I congenital cystic adenomatoid malformation (CCAM) in the left lower lobe was removed from a 11-year-old boy with a 3-month history of recurrent pneumonia. As incidental finding, a bronchioloalveolar carcinoma (BAC) was found in the lung parenchyma adjacent to the cyst. A left lower lobectomy was performed. At 18 months after surgery the patient is well and free of neoplastic disease. To the best of our knowledge, this association has not been reported previously in a pediatric patient. Malignancies complicating CCAM are rarely seen, but have been reported in adults. Including our case, eight cases of BAC and five cases of rhabdomyosarcoma (RMS) in association with CCAM have been reported so far. As CCAM can host metaplastic mucous cells, primitive mesenchymal cells and differentiated but poorly organized striated muscle fibers, it has been proposed that CCAM may act as a predisposing condition for oncogenesis. Our experience adds further support that CCAM can act as a premalignant lesion. Previous reports of both BAC and RMS in asymptomatic CCAM suggest prompt resection shortly after diagnosis.

Embryonal rhabdomyosarcoma of the lung arising in cystic adenomatoid malformation: case report and review of the literature

Rhabdomyosarcoma (RMS) of the lung is a very rare lesion, but the association with cystic adenomatoid malformation (CCAM) is unlikely to be a coincidence. Although the etiologic factors predisposing infants and children to pulmonary neoplasms are unknown, pulmonary developmental abnormalities may play a pathogenetic role. A case of embryonal pulmonary RMS is described, which was discovered within a congenital CCAM in a 22-month-old child. The hypothesis regarding histogenesis of this neoplasm are also briefly discussed. Because of the risk of malignant change, early removal of the congenital cystic lesions of the lung is advisable.

Fine-needle aspiration cytology of pleuropulmonary blastoma: case report and review of the literature

This report describes the fine-needle aspiration (FNA) cytology of a case of pleuropulmonary blastoma in a 3-yr-9-mo-old male. Pleuropulmonary blastoma is considered by most authors to be distinct from pulmonary blastoma and is a rare malignant tumor of the intrathoracic cavity. FNA smears were cellular with numerous small ovoid to spindled cells with oval to elliptical nuclei exhibiting finely granular chromatin and inconspicuous nucleoli. The cytoplasm was scant and eosinophilic with indistinct borders. Focal chondroid material and blastema-like cells were noted. The differential diagnosis suggested by the cytologic findings included rhabdomysosarcoma, teratoma, neuroblastoma, malignant mesenchymoma, pleuropulmonary blastoma, and metastatic tumor. To our knowledge, this is the first report of the cytology of this tumor.

Primary pulmonary rhabdomyosarcoma in childhood: clinico-biologic features in two cases with review of the literature

The cases of two children under three years of age with primary pulmonary rhabdomyosarcoma and no associated lung malformations are reported and a review of the literature is presented. In both, complete surgical removal of the tumor was performed and histologic examination revealed embryonal subtype. Flow cytometric assessment showed a tumor-cell diploid DNA content. Postoperative radio- and chemotherapy were carried out, but in spite of treatment both girls died because of disease progression, fourteen and nine months after diagnosis. The importance of associated cystic lung malformations and DNA content in predicting clinical outcome of primary pulmonary rhabdomyosarcoma is evaluated.

Alveolar rhabdomyosarcoma of the lung in a child

The case of a 22-month-old boy with alveolar rhabdomyosarcoma of the lung is presented. Brain metastasis and recurrence of the right pulmonary hilum and parietal pleura developed 6, 11, and 24 months (respectively) after tumor resection. Chemotherapy and radiotherapy were effective. Neuron-specific enolase was very helpful in detecting metastasis and disease recurrence. Primary pulmonary rhabdomyosarcoma can be divided into two groups: tumor in the normal lung, and tumor in cystic lesions of the lung.

Case report: primary intrathoracic rhabdomyosarcoma: a rare childhood malignancy

Primary intrathoracic rhabdomyosarcoma is a rare tumour in childhood. Three cases are presented and the radiological findings and clinical course are reviewed. The radiological manifestations are varied but a rapidly growing soft tissue mass with compression of adjacent structures is the most common. A rare association with an underlying congenital pulmonary cyst is described. The prognosis is worse than for rhabdomyosarcoma at other sites, with a predisposition for cerebral metastases.

Childhood primary pulmonary neoplasms

Nine children (6 boys, 3 girls) were diagnosed with a primary endobronchial or pulmonary parenchymal neoplasm. The average age at diagnosis was 9 years. Presenting complaints included cough (7), fever (5), pulmonary infection (3), respiratory distress (3), weight loss (2), pain (2), and hemoptysis (1). Pulmonary x-rays showed persistent atelectasis, pneumonic infiltrates or mass lesions. A computed tomography scan was performed in 8. Five of six endobronchial tumors were diagnosed with bronchoscopy and biopsy. Treatment consisted of thoracotomy and pulmonary resection in 7 cases and laser resection in 2. The pathologic diagnoses were bronchial carcinoid (3), bronchial mucoepidermoid carcinoma (1), inflammatory pseudotumor (plasma cell granuloma) of the bronchus (2) and of the lung parenchyma (1), fibrosarcoma (1), and rhabdomyosarcoma (1). Postoperative chemotherapy was given only to the patient with pulmonary rhabdomyosarcoma; this child died. One child has developed a local recurrence while 7 children are alive and free of disease at an average of 2.4 years postresection. Pulmonary neoplasms are unusual in the pediatric age group and represent a wide spectrum of pathology. Including the present series, 383 tumors have been described. Seventy-six percent were malignant. Early investigation and surgical intervention are essential in children with persistent pulmonary symptoms or x-ray abnormalities. In most cases, the prognosis is excellent with complete surgical resection; however, malignancies other than bronchial adenoma are associated with significantly mortality.

Rhabdomyosarcoma arising within congenital pulmonary cysts: report of three cases

Over the past 9 months, three cases of primary pulmonary rhabdomyosarcoma have been treated at British Columbia Children's Hospital. Two patients (aged 24 and 37 months) presented with spontaneous pneumothoraces and had cystic changes in the affected lung on chest radiograph. The third patient (aged 42 months) was evaluated for chronic cough, fever, and failure to thrive. Chest x-ray showed a large mass in the left lower lobe as well as mediastinal adenopathy. All three of these lesions originated within congenital lung cysts, one a peripheral bronchogenic cyst and the others cystic adenomatoid malformations. This report suggests that there is a significant risk for the development of rhabdomyosarcoma within malformed pulmonary tissue.

Childhood pulmonary blastoma: a pleuropulmonary variant of the adult-type pulmonary blastoma

Two fatal childhood cases of the rare pulmonary blastoma are reported. One was associated with a congenital cystic adenomatoid malformation. Both neoplasms extended to involve visceral pleura and were entirely composed of blastemal and mesenchymal elements without recognizable neoplastic epithelial components. The mesenchymal component in both instances consisted of malignant rhabdomyoblasts, undifferentiated mesenchyme, and differentiated, apparently benign, cartilage. Review of the literature suggests that these features may be specific for the childhood forms of pulmonary blastoma. It is further suggested that pulmonary blastoma, malignant mesenchymoma of the lung, and primary pulmonary rhabdomyosarcoma may have a common pathogenetic origin.

Malignant mesenchymoma associated with a congenital lung cyst in a child: case report and review of the literature

Primary lung tumors are uncommon in children, and malignant mesenchymal tumors form only a small proportion of these. Leiomyosarcomas occur more commonly than rhabdomyosarcomas, whereas malignant mesenchymomas are exceedingly rare. Of the total number of primary pulmonary rhabdomyosarcomas and malignant mesenchymomas of lung reported in children, 50% have occurred in association with congenital lung cysts. The relationship between abnormal morphogenesis and neoplasia is well documented in the kidney. A similar relationship may exist in the lung between cystic parenchymal maldevelopment and embryonal mesenchymal tumors. We report a 4-year-old boy with a malignant mesenchymoma of lung arising within a congenital lung cyst; one similar case has previously been reported to our knowledge.